CBX3 is a component of heterochromatin‐associated proteins that binds specifically to trimethylated lysine 9 of histone H3 (H3K9me3), leading to the formation of heterochromatin.[20] CBX3 modulates numerous cellular processes, such as cell growth, cell differentiation, and DNA damage, by suppressing the expression of various genes.[20] CBX3 has recently been identified as a potential marker of carcinogenesis due to its high expression in several human cancer types, including colorectal cancer, lung cancer, hepatocellular carcinoma, and pancreatic cancer. The gene discussed is CBX3; the disease is colorectal cancer.